Fair enough OZ, it feels like the plastic block is fairly solid, I put a lot of pressure on the plate and there was no discernible movement. The DMT plates themselves are on some sort of metal which is about 2mm thick. The size may be slightly prohibiitive on normal hones but are fine for the ones I have, they are only 40mm by 100mm. Not sure how they would be on others, I will bring them over the next time we catch up. I have also bought the 4 Welsh slate set off AJ. Looking forward to them comming in.